ECC Unit 3 Mathematical/Simulation Unit - This unit will be located in New York and distributed between Mount Sinai and NYU Courant. Only software development will be done at NCBS in Bangalore India under the leadership of Upi Bhalla. Progress in the study of physioloigcal regulatory systems has advanced to a stage where closely associated theoretical research is required. Mathematics coupled with computational simulations provides the ideal framework for this endeavor. Mathematics allows for the development of theoretical models of biological systems that can generate predictions and suggest experimental tests to either confirm or refute the models. All four of the research projects in the SBC will use computational modeling as a means of developing hypotheses and understanding experimental data. Mathematical techniques can also be used to organize and interpret experimental data, particularly in this era in which high-throughput techniques produce extremely large data sets. These observations provide compelling arguments for a mathematics/simulation unit with the ECC.